The present invention relates to a guiding catheter used in Percutaneous Transluminal Coronary Angioplasty procedures. More particularly the present invention concerns a guiding catheter having perfusion ports which are alternately covered to control the direction of flow of injected contrast medium and opened to enable the flow of the artery being treated.
In Percutaneous Transluminal Coronary Angioplasty (PTCA) procedures, a balloon catheter is introduced into an artery for the purposes of enlarging a vessel or opening a clogged artery or stuck valve in the heart or elsewhere to restore normal blood flow. A peripheral introduction of a balloon tip catheter enlarges and dilates a narrowed arterial lumen by inflating the catheter tip.
The PTCA procedure is begun by the introduction of a guiding catheter through an artery in the groin or arm. The guiding catheter is advanced to where the coronary arteries branch off the heart. Then x-ray dye medium is inserted through the guiding catheter into the coronary artery to look for blockages using an x-ray monitor. Once a blockage is found, a guide wire and then a balloon catheter is inserted to the blockage area where inflation of the balloon opens the artery to restore normal blood flow.
During PTCA, a guiding catheter may block the ostium of smaller arteries and, subsequently, block the flow of blood. Conventional guiding catheters employ perfusion ports that allow increased blood flow through the artery while the catheter is navigated through the arteries. These ports, however, reduce coronary visualization when a contrast medium is injected through the catheter into the artery of a patient.
A pre-operational technique includes injecting a contrast medium into an artery of a patient to determine the location of the narrowed lumen. When a perfusion catheter is employed, some of the contrast dye escapes through the ports; subsequently the amount of contrast dye injected into the patient's target artery is decreased. A decrease in the amount of the contrast medium causes the coronary visualization to decrease. Therefore, when an operator uses a guiding catheter with perfusion ports, the operator compromises the amount of contrast that can be injected into the artery and thereby decreases the visualization of the target artery.
Some prior art devices have been employed to control the efflux of the contrast medium from a catheter. One such device employs two groups of one-way valves. One group of valves prohibits the flow from the arterial lumen to the lumen in the catheter. The other group prevents flow from the catheter lumen to the arterial lumen. Another prior art device uses a one-way check valve inside the main catheter to enable blood to flow through the arterial catheter only when the heart is pumping and prohibit the flow of the contrast from the catheter lumen through the ports.
A need exists for a simple effective device for limiting the loss of contrast dye into the aorta or untargeted arteries while enabling blood flow through an artery in which the guiding catheter is located.